Review notes: My first impressions of the sound of the Angle & Curve CarbonCans (ACCC) are based on direct comparisons to other headphones - the v-moda M100 and XS, the FAD Pandora VI and IV, the Beyerdynamic T1 and T90, the AKG K812 and K712, and notes that I've accumulated from many prior reviews. I'll describe how I relate to the ACCC (i.e. my personal tastes and how I use the headphone) only after covering all of the objective issues.

When I first listened to the Angle & Curve CarbonCans (abbreviated ACCC here), I thought of the classic Beyerdynamic headphones - the DT100, DT150 etc. Those are very midrange-oriented, based on my last 2 years' experience with the warmer class of headphones such as the MrSpeakers Mad Dog, ATH ESW9a, B&O H6, B&W P5, Beyer DT770-32, Sennheiser Momentum, and so on. The ACCC is different - if you listen mostly to classical, jazz, acoustic, and other similar genres, you might be interested in this headphone. If your taste is more common - most popular music, EDM, urban etc., you're much less likely to appreciate the ACCC. I buy headphones that I'm curious about regardless of how they sound, but I do try to choose something that's likely to be inoffensive at the very least. When one of my purchases turns out to be far enough from my preferred signature, I'm not shy about using EQ to adjust the bass or treble etc. to get closer to what I like.

For this review I'm not using EQ or tone controls of any kind, so when I state that the ACCC is very midrange-oriented, it's not like any other headphone I've used recently - perhaps a bit like some IEM's I've used - but not headphones, excepting the classic Beyers I noted above. I have to emphasize here that the ACCC sound isn't deficient (unless its signature doesn't match your needs) - it's actually something I can adjust to and enjoy immensely, with musical tone and detail that's free of the most common things that plague other headphones - muddy, boomy, inarticulate bass, crispy, peaky, harsh treble, and oddly-colored midranges. The ACCC is a very smooth performer. One important thing that affects bass strength with this headphone is the headband clamp - it's very light on my average-size head, so other users' experiences could be a little different.

I gave the ACCC about 24 hours of continuous play at medium-loud listening levels for purposes of "burn-in". Some of the lower-cost headphones I've had change quite a bit during the burn-in process, but the ACCC sound has changed very little or none at all. Of course it's possible that headphones could be played at some length on a QC bench at the factory - it doesn't cost anyting except a little extra space and a series of headphone jacks to provide the sound. Isolation is less than what I've experienced with some of my closed on-ear headphones, but where I hang out most days about 100 yards from a busy freeway, the isolation is enough to keep the noise well below the music level. Leakage is low enough that the ACCC should be playable at moderate volumes in libraries, in quiet offices, and on public transport.

The ACCC is average in weight for an on-ear headphone, which is to say it's pretty light. The clamping force is light as noted above, which means it gets comfortable very quickly and stays securely in place with activity that doesn't involve rapid head movements. This is an ideal portable headphone in the sense that it can be pulled off the head when not in use, and worn around the neck with no comfort issues. This is important to me because I like to go places without having to deal with a bag or case - just put the headphone around my neck and drive to work, then set the headphone down on the desk. The range of adjustment for different head sizes is nearly 2 inches on each side, where my average size head fits at 3/4 inch from the largest size. The cable is double-entry and non-detachable, but seems sturdy enough for average use if not abused. The cable has a mic on the left side, but no music player controls. The 3.5 mm straight plug has the extra conductor for the mic, like Apple-compatible cables.

In previous reviews I've included the following music examples with comments about how the headphones sound with each track. My suggestion is instead of reading each one as an absolute unto itself, you could compare my notes here to those other reviews and see how the ACCC compares with each individual track.

Animotion - Obsession (1980's New Wave/Techno): The upper bass synth has excellent detail and tone, and both male and female vocals sound natural without favoring either. The ACCC plays this very well.

Bauhaus - Bela Lugosi's Dead (~1980): Strong midrange sound effects - this is a good worst-case test for resonant-type sounds in the most sensitive midrange area. Handled perfectly by the ACCC.

Beethoven Symphony 9, Solti/CSO (1972): Excellent overall sound. Of special note here are the bass impacts beginning around 10:30 of the fourth movement. Those impacts are soft and well in the background, and you can barely feel the weight they carry with the ACCC.

Black Sabbath - Iron Man (Classic Rock): Very good instrumental detail and the vocal sounds very natural. As with most classic rock tracks, there is very little or no deep bass. The ACCC plays this music smoothly, and the lack of deep bass doesn't unbalance the treble.

Boz Scaggs - Lowdown (1976): Great sound quality - this is a good test for any nasality in the midrange. Handled extremely well by the ACCC.

Cantus - Danny Boy (Traditional/Male Choral/Acapella): The ACCC plays the voices with minimal low end weight, yet they sound natural since there is no added emphasis of the lower register of the male voices on this track.

Cath Carroll - Moves Like You (1980's New Wave/Techno): This track's percussion and voice are crisp and well-balanced, and there's a good sense of space or soundstage around the voices and instruments. The ACCC reproduces the space and detail very well.

Catherine Wheel - Black Metallic (~1991): Goth with industrial overtones - I like this since it's a great music composition and the sound effects are smoothly integrated into the mix. This may sound distorted or mushy with some headphones, but the ACCC renders the deliberate instrumental distortions clearly.

Chris Isaak - Wicked Game (Pop/Rock): The ACCC plays this high treble energy recording very smoothly - the voice and instruments are very detailed but not edgy - very musical in fact.

Chromatics - I'm On Fire (Synth-Pop, female lead): This track has a good amount of space around the voice and instruments, making for a very pleasant stereo image. The voice is excellent, and the tambourine is clearly recognizable.

David Hazeltine - Fur Elise (Jazz): A very high-quality recording from HDTracks. The ACCC reproduces the instruments smoothly with a spacious ambiance. The wire-brush-on-cymbal harmonics are normally very extended and detailed, but the ACCC needs a slight treble boost to get the full upper-harmonics effect

Grieg (Beecham-Royal Philharmonic) - Peer Gynt-Solveig's Lullaby (Classical): This very old (late 1950's) stereo recording must have been made on the most expensive gear in the world, since the overall sound quality and especially Ilse Hollweg's amazing voice are as close to "being there" as I've heard with some of the better classical recordings made since the year 2000. The ACCC plays this music perfectly.

Hans Zimmer - Dark Knight-Aggressive Expansion (Soundtrack): The percussion in this track hits pretty hard, and while the bass tones beginning around 0:45 have an ultra-deep "shuddery" kind of sound and feel with most popular headphones, they don't have that kind of weight with the ACCC.

Heaven 17 - Let Me Go (1980's New Wave/Techno): The bass instrument (guitar?) has excellent detail, and the voices and ambiance have a "you are there" quality that's uncommon in early 1980's pop music. The ACCC plays this track perfectly.

Hugo Audiophile - 15-16 (Electronic): I'm not sure what the 15-16 stands for - perhaps track numbers from a CD album. The deep-bass tones that start around 33-34 seconds into the track reproduce lightly with the ACCC. This is a great recording for evaluating whether a headphone's bass will be sufficient for most environments, since for many headphones that have a weaker bass, the deep bass gets absorbed and mostly lost when the environment contains a lot of low-frequency energy.

Jimmy Smith - Basin Street Blues (early 60's): This track has several loud crescendos of brass and other instruments that don't sound clean and musical with some headphones. The ACCC provides a good reproduction. Listen particularly to the second crescendo at 15 seconds in for best-case detail. I'd like to emphasize that these crescendos are probably the worst-case test I have for instrument separation and detail, and the ACCC resolves those pretty well.

Kellogg Auditorium, Battle Creek Michigan, Aeolian-Skinner Organ (1933) - Pedal, 32', Resultant, Arpeggio: This 16 hz organ pedal tone differs from other music tones in that you won't "hear" the tone - you'll only feel it. Although most music tones have harmonics (including this one), the harmonics from this tone will be too weak to provide any "feel", so whatever you actually hear would not be part of the fundamental 16 hz tone. There are ~30 hz sounds in the outdoor environment in big cities, generated by large trucks, buses, and subway trains, and they have a quality of "rumble" that's similar to some deep-bass tones found in music. This 16 hz organ tone is easily distinguished from those sounds when compared on a headphone that has good undistorted response at 16 hz. The ACCC plays the harmonic detail well enough, but the fundamental tone (the weight) is very light.

Mantovani - Sunrise Sunset (Easy Listening, ca. 1972): A master musician and conductor who specialized in light classics and orchestral pop music, Mantovani's accomplishments were overshadowed by music critics who couldn't tolerate the notion of "light classics" or "semi-classical" music, even when those recordings were no threat to the classical music genres. In any case the later Mantovani recordings from the mid-1960's through mid-1970's had the advantage of being mixed for much better hi-fi systems than those which the music critics possessed at the start of the Long Playing (LP) record cycle. Here in 2015, at least some of those digital remasters have improved the sound further, although it's not always the case. This track as played on the ACCC is a perfect example of the sheer musicality lurking in those later recordings, and is highly recommended for soundstage, instrumental tone, and musical balance.

Michael Tilson Thomas - Rhapsody In Blue (20th Century Classic): Great sound and soundstage, and terrific piano playing and tone. There are some very deep bass impacts starting around 38 seconds into the 17:24 length track, and while the weight of those impacts is subtle with most headphones, it's very subtle with the ACCC.

Pinback - Non Photo Blue (Pop-Rock): Crispy sound with "crunchy guitars and bashing drums" - the ACCC renders this music as well as I've heard an energetic pop-rock recording played with most headphones.

Porcupine Tree - Trains (Pop-Rock): This track opens with some nicely-detailed string sounds and a forward-sounding male voice with a higher-than-average register. There are a series of "clip-clop" effects starting at 3:19 that should sound like they were made with wooden blocks of some kind. The ACCC reproduces that sound effect pretty well.

Richard Strauss (Mester-Pasadena) - Also Sprach Zarathustra (opening) (Classical): The granddaddy of bass is in the opening 1:50 of this recording, and I've heard it only once on a large and expensive loudspeaker system in Cleveland. For most people, that experience would be indistinguishable from being in a fairly strong earthquake. The ACCC does not convey that kind of experience, but the tympani do have good impact here.

Scarlatti-Kipnis - Sonata in E Major K381 (Classical, Harpsichord): The harpsichord here is fairly bright and detailed, and the ACCC renders the tones very well.

Tiger Okoshi - Bootsman's Little House (Jazz): The trumpet here is recorded fairly close up and is somewhat bright with a significant "bite". The ACCC's reproduction is good and the close-miked piano is a treat. For comparison, I have several Maynard Ferguson tracks that feature a similarly strong trumpet with lots of brassy bite.

Trombone Shorty - Backatown (Jazz-Funk): The deep bass here doesn't have quite the impact of most popular headphones, but the low-end tonality is good and works very well with the horns and other instruments. The ACCC delivers the impacts with very modest weight and good detail, and the horns have the kind of bite that gives them a wonderfully realistic sound.